If the owners' estimates are anywhere near correct, the value of the art reported stolen from a Pebble Beach home nine days ago makes it one of the biggest art heists in U.S. history.

Collector Angelo Benjamin Amadio says art experts have told him the take may be second in the country to the world's biggest unsolved art theft: the 1990 haul from Boston's Isabella Stewart Gardner Museum that included works by Vermeer, Rembrandt and Degas and has been valued at $300 million.

The estimated value of the Pebble Beach theft has increased by millions since it was announced in a press release a week ago. The first estimates, which Amadio says were made before an inventory of the loss was completed, placed the value of the missing art at $27 million — a total based on a 2002 inventory of the collection.

By Friday, the Boston Globe reported that Vicki St. John, an attorney representing Amadio and his friend and business partner Dr. Ralph Kennaugh, said that about 30 pieces had been stolen — and the total value could now be as much as $100 million.

But Amadio said experts have told him the pieces' current value would more likely range from $60 million to $80 million.

"Put it this way: If someone had given us $80 million, we would have taken it."

Among the works listed as stolen were paintings and drawings by Rembrandt, Matisse, Miro, Renoir and Van Gogh. There might also be a Degas in the lot, he said.

The purported crown jewel of the heist is a 7-foot-long painting by Jackson Pollock that Amadio said has never been publicly displayed and may not have been included in any "catalogue raisonne," the art world's term for a listing of an artist's body of work. But private collectors "know about the piece," Amadio said.

Nancy Netzer, director of the McMullen Museum at Boston College and a professor of art history, said, "I do think it's possible that there are Pollack paintings not in the catalogue raisonne. How likely in any specific case would depend on what is known of the picture's provenance."

Amadio showed reporters several pages of paperwork that he said described the provenance and authenticity of the missing painting. The Pollock piece alone may be worth anywhere from $20 million to $60 million, he said.7

As with any large-scale art theft, there has been speculation as to how insurance figures into the loss.

One the men's two insurance agents, Jerry Seagraves of Capitola, said Thursday the men had policies covering a fair amount of art and personal articles, but he didn't know yet if the missing art was among them.

"It's a terrible catastrophe to have to go through," Seagraves said.

Arthur Dion, who for 20 years was president of the Boston Art Dealers' Association, said that while not insuring valuable works of art isn't recommended, it's not unheard of.